There really aren't any 4 ohm AVR's out there. I have a top of the line Marantz, and it is only rated for 8 or 6 ohms. Now, if you have an understanding of Ohms Law, you'll know that you can technically put a 4 ohm speaker on your AVR, but you will be limited by how much heat the AVR produces under load, and potentially by a protection circuit which will shut off the AVR to protect itself. My recommendation would be to get either a pre/pro, or an AVR with pre-amp outputs, and then get a dedicated amplifier that can support 4 ohms.

Tweaked
There really aren't any 4 ohm AVR's out there. I have a top of the line Marantz, and it is only rated for 8 or 6 ohms. Now, if you have an understanding of Ohms Law, you'll know that you can technically put a 4 ohm speaker on your AVR, but you will be limited by how much heat the AVR produces under load, and potentially by a protection circuit which will shut off the AVR to protect itself. My recommendation would be to get either a pre/pro, or an AVR with pre-amp outputs, and then get a dedicated amplifier that can support 4 ohms.

What is a "pre/pro" and how would that work in a 5:1 system? I'm not sure my AVR has pre-amp outputs, and when I look at the rear connections on new AVR's I only see one red and black analog connection, so how does that work with stereo?

JonnyQuestRacer

 
This is the back of my Denon X1300W. You can see a separate label called PRE OUT at the top. That is the port to connect to a pre amplifier, which will then feed to you speakers. I think your AVR should have something similar. 
 
Not clear what you are asking regarding stereo, but in the above (modern?) AVR you just connect one of the speakers Front L (black/red pair), and second speaker to Front R (black/red pair) and you have a basic stereo setup with 2 speakers. 

 
Thanks Jonny for the input. My current Yamaha makes no mention of PRE OUT in the back. It doesn't matter because your recommendation of the Yamaha RX-V673 made me do some research. When at Yamaha I found the RX-V683 and watched a good video about it at YouTube by Yamaha put out a year ago in March. I'm upgrading my home theater and will eventually pick up a 4K HDR LCD Full-Array 65" in March or April when the new 2018 models come out. I'm hoping to learn more about the new 'TCL' lineup. I'm going to wait a bit on getting a new AVR and see what 2018 has to offer and maybe get lucky and pick up the RX-V683 on sale in March or April.

Tweaked

007vsMagua

Tweaked
There really aren't any 4 ohm AVR's out there. I have a top of the line Marantz, and it is only rated for 8 or 6 ohms. Now, if you have an understanding of Ohms Law, you'll know that you can technically put a 4 ohm speaker on your AVR, but you will be limited by how much heat the AVR produces under load, and potentially by a protection circuit which will shut off the AVR to protect itself. My recommendation would be to get either a pre/pro, or an AVR with pre-amp outputs, and then get a dedicated amplifier that can support 4 ohms.

What is a "pre/pro" and how would that work in a 5:1 system? I'm not sure my AVR has pre-amp outputs, and when I look at the rear connections on new AVR's I only see one red and black analog connection, so how does that work with stereo?

A pre/pro is a pre-amp/processor. It is essentially the same as an AVR minus the amplifier section. This allows you to purchase separate amplifiers which last forever, and then just upgrade the pre/pro over time as new features come out. 

OK, thanks. That sounds like the way to go when building a high end system.

Tweaked

007vsMagua

Tweaked

007vsMagua

Tweaked
There really aren't any 4 ohm AVR's out there. I have a top of the line Marantz, and it is only rated for 8 or 6 ohms. Now, if you have an understanding of Ohms Law, you'll know that you can technically put a 4 ohm speaker on your AVR, but you will be limited by how much heat the AVR produces under load, and potentially by a protection circuit which will shut off the AVR to protect itself. My recommendation would be to get either a pre/pro, or an AVR with pre-amp outputs, and then get a dedicated amplifier that can support 4 ohms.

What is a "pre/pro" and how would that work in a 5:1 system? I'm not sure my AVR has pre-amp outputs, and when I look at the rear connections on new AVR's I only see one red and black analog connection, so how does that work with stereo?

A pre/pro is a pre-amp/processor. It is essentially the same as an AVR minus the amplifier section. This allows you to purchase separate amplifiers which last forever, and then just upgrade the pre/pro over time as new features come out. 

OK, thanks. That sounds like the way to go when building a high end system.

It does tend to cost a bit more money, but 4 ohm speakers are very hard to drive with the average AVR.

Here are the speakers and arrangement I'm looking at. As I get on in age my hearing isn't what it used to be. I'm renting so when I'm trying to enjoy a movie later in the night I'm unable to make out the dialog because I don't want to turn up the volume. I either turn on subtitles or use my Sennheiser wireless headphones. I hate subtitles unless it's a great foreign movie and I just don't enjoy wearing headphones. The Sennheiser's sound OK but I want surround. I've read good reviews about how dialog in movies is greatly improved using the ELAC speakers and I want to give it a go and just want to know how to best use them. I want to be somewhat ready for the future when it comes to AV receivers and I don't mind spending a little money for the brain that will run my system well into the future.
 

 

looks good, do you have a center speaker? center speaker would help a lot with dialogues. (and you can still play in stereo when you want)

Here is a quick update on how my system is coming together. I'm still waiting for my Onkyo_TX-NR777 to arrive from Amazon. I ordered it over two weeks ago. The first shipment got lost in Hodgkins, IL and after waiting awhile I finally cancelled the order with Amazon and reordered the NR777 and should have it by Friday. Once I get my AVR I'll finally be able to test the speakers.
 
From the picture you can see how I set my two 'Minimus-7' speakers to handle the two Atmos speakers [ceiling bounce]. I live in a wood framed three story apartment building on the first floor and found a nice wall to arrange everything to fit the new 65" TV I'll be getting this Spring.
 
I'm not sure how Dolby Atmos will work in my apartment. My ceiling is eight feet tall and flat, but it has that cheap pop-corn finish favored by contractors. A pop-corn ceiling does help with acoustics, so I'm sure it will affect bounce sound. I saw a cool video on YouTube and a guy used an eight foot long piece of 3" PVC white drain pipe and made a post with a base plate and top plate and mounted his speakers next to the ceiling without having to drill any holes into the ceiling. If bounce doesn't work for me I've already worked up a simple design for using 2 x 3" x 8' PVC pipe. My idea is to drill 3/8" holes at the base and top of the pipe for running the speaker wire, give it a quick #150 sanding, and then two nice coats of black latex paint. The thing that worries me most about Bounce is what the tenant above might think?